Armstrong Seadrome


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16 January 2008
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Not sure if this thread went in Naval Projects or Prewar. So I took a chance.

An idea ahead of it's time. Aircraft carriers were still a pretty new idea. Project Habbakuk was about 8 years away And routine passenger jet travel was years away. Still very interesting concept by Armstrong, considering the era.

I first heard of this when I was in fifth grade in a book (60's vintage) called Engineering Marvels or something like that. Also had a section on Project Habbakuk and another on peroxide powered subs. I used to have the Air and Space article from who-knows-when (early or mid 90's???) on the Armstrong Seadrome. Don't have it any more.

Funny thing is I still remember hearing about the SeaBase concept about 10 years back. Greatly reminded me of the Seadrome. But I guess we can file SeaBase right there with the good 'ol Arsenal Ship (I so wanted orders to that, had it been built :eek:).
The logical progression of the Seadrome.,8045.0.html
Originally found by XP67_Moonbat:




FUNDS recently appropriated by the government have put the United States Department of Commerce, Aviation Branch, squarely behind the immediate development of a chain of five floating airports which will span the Atlantic for regular airways service.

This recently announced appropriation, amounting to $1,500,000 was negotiated by Eugene L. Vidal, Director of Aeronautics of the Department of Commerce, in behalf of Edward R. Armstrong, inventor of the seadrome, and completes a 16 year fight to gain recognition for a project which both Mr. Vidal, a competent and experienced airways operator, and Mr. Armstrong solidly believe in. As well, it will provide work for a great number of unemployed, as 80 per cent of the cost of such development projects goes to labor.

This $1,500,000 is for immediate experiments with a quarter-section ocean landing-field and ends a sixteen-year struggle for recognition of the seadrome system. The final plan calls for a $30,000,000 outlay by the government, contingent on the success of the preliminary experiments now under way.

According to information gathered by this member of the staff of Modern Mechanix and Inventions, the ultimate plan calls for similar seadrome stations in the Pacific and other oceans, giving the United States an international supremacy of the air lanes. Great Britain and France both gave the Armstrong plan serious consideration but failed to adopt it.

The proposed system calls for five Armstrong seadromes at 500 mile intervals from the Atlantic seaboard here to the western coast of Europe. Each drome will cost $6,000,000.

Back in 1927 when Armstrong completed his first models of the floating deck, he intended to have hangars and hotels on the six-acre surface. But the design which has been accepted by the government calls for a vacant deck, with hangar and hotel accommodations confined to two or three decks below the surface.

The seadromes will be 1,225 feet long and 300 feet wide. An elevator will take planes from the surface to the underdeck hangars. This specially-designed elevator will adequately handle planes with wing spans up to 120 feet This flying deck will be supported in place by a number of ballast tanks sunk sufficiently below the water so that the flotation arrangement will be unaffected. That was the inventor’s predominant problem, constructing his float so that it would not shift and toss with the huge waves.

A truss system of anchorage will hold the big deck by means of cables to a 1,500-ton weight on the bottom of the ocean. The truss-like arrangement will consist of twenty-eight buoyancy tanks floating far beneath the ocean’s surface. In turn these will be linked to the deck by means of cast iron columns streamlined into an oval shape above the mean level of the waves and circular below.

Columns 300 Feet Deep

Underneath the buoyancy tanks these columns will continue downward a hundred feet to the ballast chambers which will be stabilized by iron ore. The complete column, including the ballast sections, will be over 300 feet in depth.

Mr. Armstrong has taken advantage of a well-known principle in the construction of his ocean island. Ocean waves are surface disturbances only, while water in the depths is still.

“A model of the proposed seadrome was constructed and tested together with a model of the steamship Majestic, built to the same scale,” Mr. Armstrong said.

“Under test conditions it was found that the seadrome was unaffected by any combination of waves up to and including those equivalent to 180 feet in height. The model of the Majestic on the contrary was practically swamped in waves exceeding 80 feet in height.”

The engineers of the Seadrome Ocean Dock Corporation associated with Mr. Armstrong estimate that 125,000 tons of iron and steel will be required to erect five airports and anchorages.

30 Hours New York to London

The seadromes will have radio stations and radio beams to guide the air-liners in inclement weather.

Attached to each seadrome there will also be sea-going cutters of the Coast Guard type for emergency as well as auxiliary duty. The floating decks will have weather stations.

At the present time the quarter section of a seadrome is being constructed behind the Delaware Breakwater. When it is finished early next summer it will be towed out to sea for the tests. If it comes up to the expectations of its sponsors, the three other sections will be built and the entire seadrome assembled. In turn work will then be started on the rest of the ocean airports.

Mr. Armstrong estimates that a 24-hour service can be maintained on the Atlantic Ocean, but he further modifies that calculation in plotting the trip between New York and London. He intends to make that journey a 30-hour trip in eight jumps of 160 miles per hour.
Articles from 1929 and 1930 on the concept:
This concept is almost the same as the "SeaBase" relocatable offshore platform;

It's also notable how similar the flared deck is to the ones later used on Supercarriers, starting with the Forrestal class.

Everything that's old is new again! ;)
Anybody remember a book, from about the mid 60's, possibly called "Engineering Wonders Of The World" or something along those lines? I distinctly remember it had a full chapter about Armstrong and Habbakuk. Very good book. That's how I learned about the Walter U-boats as well, though I vaguely remember the chapter being called "Rocket Submarines" or some such deal.
Anyone else remember this book?
XP67_Moonbat said:
..though I vaguely remember the chapter being called "Rocket Submarines" or some such deal.
Certainly not the book, you mentioned, but the term "Raketen U-Boot" (rocket submarine) was used in
German books (not really specialist books ten ..), too, because Hellmut Walter was at least as well known
for his rocket engines, as for his designs of submarines.
At Jemiba, yeah the chapter, I vaguely seem to remember being called "Rocket Submarines", in English. Or something along those lines.
Mr Armstrong's Stepping Stones Pt 1
Ralph Pegram opens a two-part series on Canadian-born inventor Edward Armstrong’s ambitious inter-war scheme to develop a chain of "Seadromes" across the Atlantic [...]
Source: The Aviation Historian, Issue No 47, pages 86 - 95

Reminds me of the 1932 German film "F.P.1". :cool:


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